Winder for rolling sheets of material, especially for winding paper or cardboard sheets into reels

ABSTRACT

A winding machine for winding rolls of web material in which the rolls are supported by at least one roller beneath them and at least one support roller can be brought into engagement from the roll from beneath and is provided on its surface with a compressible layer of porous synthetic material.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national stage of PCT/EP 97/06111 filed Nov. 5,1997 and based upon German National application 196 49 354.4 of Nov. 28,1996 under the International Convention.

TECHNICAL FIELD

The invention relates to a winding machine for winding a web ofmaterial, particularly a paper or cardboard web into a finished roll.

BACKGROUND OF THE INVENTION

Various types of winding machines are known for the production of woundrolls from paper or cardboard webs longitudinally sectioned intoindividual webs.

In the so-called winding machines with carrying rollers, two drivencarrying rollers form a roller bed in which the winding rolls lie inrows with aligned axes on the carrying rollers, which therefore bear thetotal weight of the winding rolls (DE 43 34 029-A). The winding hardnesswhich is decisive for roll quality (=surface pressure between the layersof a winding roll) is clearly dependent on the tensile stress exertedduring winding of the outermost layer. During winding, this tensilestress is produced by the driven carrying rollers and is decisivelyinfluenced by the line load and the geometric conditions in the nipbetween a winding roll and a carrying roller, since in the nip anadditional stretching of the web is generated. The line load is thecontact pressure of the winding rolls which is standard for a certainwinding roll width, expressed in N/m. Since the stretching in the nipincreases with the increasing roll weight, its value limits the maximalfinal diameter of a finished roll which is free of defects and woundwith the desired winding hardness.

In order to be able to keep the line load within a desired low range, inwinding machines with support rollers, on both sides of a centralsupport roller, winding stations consisting each of two carryingelements are arranged, to which the individual webs are alternately fedfor winding. Each winding station holds a winding roll by means of guideheads rotatably supported on the carrying elements, the heads beinglaterally introduced into the winding rolls. Thereby the guide headsbear all or part of the weight of the winding rolls. The balance of thewinding roll weight—which can tend towards zero—is supported by thesupport roller. Such winding machines with support rollers make possiblethe winding of rolls with a large diameter and/or of very sensitivepapers with the desired quality (DE 40 12 979-A1).

The support roller in winding machines with support rollers and one ofthe carrying rollers in the winding machines with carrying rollers serveat the same time as a contact rollers, which together with the windingroll form a roller nip through which the web is fed to the winding roll.A contact roller will have at the same time the function of preventingair from being sucked into the winding rolls, i.e. to seal off thewinding rolls over their entire width.

In winding machines with carrying rollers, the tensile stress in the webrequired for the winding hardness is produced by the carrying rollersacting as a peripheral drive. The carrying rollers than can be connectedwith a rotary drive. In the winding machines with support rollers, thedriven support rollers also act as a peripheral drive. In order to beable to additionally influence the winding hardness, particularly withinthe range of small winding roll diameters, it is known to provide theguide heads with rotary drives. By means of the rotary drives of theguide heads working as central or core drives it is possible to generateadditional torque for influencing the tensile stress at each windingroll.

From the WO 97/28075 a winding machine with carrying rollers is knownwith two permanently driven carrying rollers. One of the carryingrollers has a shell made of a deformable layer consisting of a cellularplastic material with a plurality of evenly distributed pores and wit acompression modulus κ of less than 10 MPa. The shell layer made of avolume-compressible material reduces the nip-induced stretching of theoutermost layer of the winding roll in the roller nip to the carryingroller. In this way the winding of rolls with a larger final diameter ismade possible, without damaging the paper or cardboard web and withoutthe occurrence of winding defects in the wound rolls.

From WO 93/15007 it appears that in the case of larger winding rolls(roll widths exceeding 2 m, roll diameter more than 1000 mm), tears andcreases can occur in the area of the roll core, if the roll weight borneby the guide head is too large. Therefore in a winding machine withsupport rollers it is proposed to additionally support the winding rollsbelow their center of gravity by means of an overpressure generated bycompressed air, at a roll diameter of at least 1000 mm.

The WO 95/32908 describes a winding machine with support rollers whereinat the start of the winding process against the winding rolls pressureis exerted from above by rollers, which are swung downwards and fromthis point on support the winding rolls from underneath. Either rollerpairs around which belts are revolving or which have a special softcoating are used.

In all known winding machines, the elements which are not primarilyinvolved in the production of the desired winding hardness, such aselements for holding the winding rolls, for the support of the rollweight, for avoiding winding defects, etc., have at the same time aconsiderable influence on the winding hardness which is decisive indetermining the quality of the wound rolls, or they are constructivelyvery expensive.

OBJECT OF THE INVENTION

It is the object of the invention to provide a winding machine by meansof which also heavy winding rolls of sensitive papers can be wound witha high winding quality and speed, without extensive constructiveefforts.

SUMMARY OF THE INVENTION

This object is achieved by providing in addition to the usual support orcontact roll which engages the winding roll one or more freely rotatablesupport rolls engage the winding roll from below and extend parallel tothe contact roll.

In the winding machine of the invention, one support roller takes overthe secondary tasks such as holding of the winding rolls and/or takingup the winding roll weight, without noticeably influencing the windinghardness. If it has a drive, then the latter serves only to accelerateit to a peripheral speed which is synchronous to the winding roll and/orto achieve a hard start of the winding process in the core area. Thedrive can then be uncoupled, in order to switch the support roller tofree running, so that no torque which could influence the windinghardness is generated during winding outwards of the core area.

The contact roller resting against the winding roll can be designed sothat it can be limited to its most important functions, namely theguidance of the web on the winding roll and the prevention of airsuction into the winding roll. The tensile stress of the web requiredfor the desired winding hardness can be produced during winding by aperipheral drive and/or by means of a center/core drive, whose designdoes not have to take into consideration the secondary tasks of winding(holding of the rolls, weight takeup). Naturally this does not excludethe fact that, depending on the paper or cardboard type to be wound, thecontact roller can assume additional functions; particularly to work asa peripheral drive and/or to take up a part of the winding roll weight.

Winding machines with carrying rollers with a second carrying rollerdesigned according to the invention as a support roller have the furtheradvantage of being capable to wind also sensitive paper types at highproduction speeds. In the case of sensitive paper types with a highfriction coefficient between layers, which do not allow layerdisplacement between the outer layer and the inner layers of a windingroll, vibrations can occur depending on the winding speed. Thevibrations are triggered by the differential speed between the twodriven carrying rollers and limit the production speed to very lowvalues.

BRIEF DESCRIPTION OF THE DRAWING

The drawing serves for explaining the invention with the aid ofembodiments represented in a simplified manner:

FIG. 1 shows a side view of a winding machine with support rollersaccording to the invention.

FIG. 2 shows an enlarged detail of FIG. 1.

FIG. 3 shows schematically a side view of a winding machine withcarrying rollers wherein the web is fed from underneath through the gapbetween the carrying rollers.

FIG. 4 shows a winding machine with carrying rollers with an alternativefeeding of the web.

FIG. 5 shows a winding machine with carrying roller having a thirdcarrying roller serving as a support roller.

SPECIFIC DESCRIPTION

In the winding machine with support rollers represented in FIGS. 1 and2, the paper or cardboard web 1 with a width of several meters is pulledoff a supply roll, subdivided into individual webs by means of alongitudinal cutter 2 and subsequently wound into winding rolls 3. Thewinding rolls 3 are arranged in two winding lines on both sides of theapex line of a driven support roller 4 made of steel having for instancea diameter of 1500 mm, on which they are supported during winding andwhich bears the roll weight entirely or partially. Each winding roll 3is held by rotatably supported guide heads 5 introduced at both sides inits winding core, and which are fastened to the sliding carriage 6. Thesliding carriages 6 are each supported on carrying elements 8 andmovable approximately radially with respect to the support roller 4 bymeans of a piston-cylinder unit 7. Each pair of these carrying elements8, which are movable transversely to the travel direction of the web 1for adjustment to various web widths, form a winding station at whichwhere one winding roll 3 is being wound.

The support roller serves as a contact roller on which the winding rolls3 rest under pressure during winding. It forms with each winding roll 3a roller nip into which each individual web 1 is fed to the pertainingwinding roll. At the same time the support roller 4 seals off eachwinding roll 3, in order to prevent air from being pulled in duringwinding. A support roller as a contact roller has the additionalfunction to act as a peripheral drive, i.e. rotate turn the windingrolls 3 during winding and to generate the tensile stress required forthe winding hardness. In order to additionally influence the windinghardness, particularly in the core area of a winding roll 3, on thesliding carriages 6 additional rotary drives 9 for the guide heads 5 areprovided. For various paper types the desired radial course of thewinding hardness can be achieved without the additional rotary drives 9,then guide heads which are supported to rotate freely without rotarydrives 9 are used.

At a distance from the support roller 4, on each side in the frame 10 ofthe winding machine a crossbeam 11 is arranged, which by means of apiston-cylinder unit 12 a can be raised and lowered. For each windingstation a sliding carriage 12 is supported on the crossbeam 11 so thatit can be moved transversely to the web 1. On each sliding carriage 12 aswivel arm 13 is linked, which at its end bears a pair of pressurerollers 14, which by means of a piston-cylinder unit 15 can be swungtowards the periphery of a winding roll 3 in order to enhance the lineforce at the contact line of the winding rolls 3 on the support roller 4for the purpose of increased winding hardness, in the initial phase ofthe winding process when the contact weight is not yet sufficient. Thepiston-cylinder units 15 are capable to swing the pressure rollers 14upwards in a neutral rest position, as shown in the figures. In order toremove a finished winding roll 3 from the winding machine, the crossbeam11 with the thereto fastened pressure rollers 14 can be sufficientlyraised.

In order to be able to limit the roll weight borne by the guide heads 5,on each side of the winding machine additional support rollers 16 arearranged next to the support roller 4 and axially parallel thereto,which are supported to move from underneath against a respective windingroll 3. Each additional support roller 16 consists of a carrying element19 which is a hollow cylinder made of a solid material, particularly ofsteel, on whose outer shell a layer 20 with limited deformability, madeof a cellular plastic material with a plurality of evenly distributedpores, is applied. The plastic material consisting of a cellularelastomer, particularly polyurethane, has a compression module of κ ofless than 10 MPa, preferably between 1 MPa and 5 MPa. The size of thepores is less than 5 mm, preferably between 0.05 and 1 mm. Preferablythe pores in the deformable layer are partially open, i.e. connected toeach other and partially closed. The proportion of open pores rangesbetween 30% and 70%, and preferably amounts to 50%. The ratio of openpores to the closed pores determines the compressibility as well as thecapability of the layer to disperse the heat generated inside, in orderto avoid undesirable overheating. The above-mentioned parameters haveproven to be particularly suited.

The diameter of the additional support rollers 16 equals 300 mm to 600mm, preferably approximately 400 mm, the radially measured thickness ofthe deformable layer 20 ranges between 10 mm to 40 mm, preferably 15 mmto 25 mm. Advantageously to each pressure roller sliding carriage 12 oneadditional support roller 16 is assigned and has an axial lengthcorresponding to the length of the pressure rollers 14, approximately400 mm in the example. Each additional support roller 16 is supported onthe pertaining pressure roller sliding carriage 12 so that it can beswung upwards and pressed with a controlled force against the undersideof a winding roll 3 by means of a pneumatic piston-cylinder unit notshown in the drawing. The way it is supported on the pressure rollersliding carriage 12 has the advantage that the additional supportrollers 16 are therewith automatically set in a transverse position. Asa rule several axially aligned additional support rollers 16, arrangednext to each other, support a winding roll 3 over its entire axiallength which can reach up to 3.5 m.

In order to achieve a friction free contact at the winding rolls duringwinding, each additional support roller 16 is connected to a rotarydrive which can be turned on and off, by means of which its peripheralspeed can be synchronized prior to its contact with a winding roll 3with the peripheral speed of the latter. Subsequently the automaticsynchronizer is turned off and the additional support roller 16 liesfreely rotatable against the respective winding roll 3.

Since for the removal of a full winding roll 3 the pressure rollercrossbeam 11 with the elements fastened thereto has to be raised, eachadditional support roller 16 can be receivable in a corresponding recessof the crossbeam 11 (see the broken line position in FIG. 2). Alladditional support rollers 16 of one winding line are therefore movedupwards with the crossbeam 11 into a position wherein below thecrossbeam 11 there is a sufficient free space through which a fullywound winding roll 3 can be removed from the winding machine.

At the start of the winding process the crossbeams 11 are lowered intotheir lower position and the pressure rollers 14 are moved towards thewinding rolls 3, in order to increase the line force at the contactpoint with the support roller 4. When the supported weight of thewinding rolls 3 has reached a certain value, at first the further weightincrease is compensated in such a way that by means of the retractingpiston-cylinder unit 7 a relieving force is applied to the guide heads5. Starting from a maximal roll diameter of approximately 1000 mm at thelatest, a further relief takes place due to the additional supportrollers 16, so that the roll weight borne by the guide heads 5 does notincrease too much. For this purpose the additional support rollers 16are removed from their rest position in the crossbeam 11, accelerated toa peripheral speed synchronized with the peripheral speed of the windingrolls 3 and subsequently pressed from underneath against the windingrolls 3. With the increasing diameter of the winding rolls 3 theadditional support rollers 16 are correspondingly guided—as shown inFIG. 2—, preferably by a combined swing and vertical motion. The lattermotion can be achieved through a linear vertical movement of thepressure roller cross beam 11.

The relieving force of the additional support rollers 16 is controlledby the upwards pushing pneumatic piston-cylinder units so that thedesired distribution of the winding roll weight on the support roller 4,the additional support rollers 16 and the guide heads 5 is achieved. Theweight distribution is controlled depending on the diameter, in order toachieve the desired winding buildup.

After the winding process is concluded, at first the additional supportrollers 16 are immersed into the crossbeams 11. Subsequently thecrossbeam 11 with the additional support rollers 16 and the pressurerollers 14 is moved upwards into an upper parking position, in which thewinding rolls 3 can be removed from the machine.

FIGS. 3 and 4 show a winding machine with carrying rollers. which has adriven carrying roller 19 as a contact roller. In addition to this firstcarrying roller 19, an axially parallel support roller 20 is arranged,which together with the first carrying roller 19 forms a roller bed,wherein the winding rolls 3 are lying on the rollers 19, 20 duringwinding. Just like the first carrying roller 19, the second carryingroller 20 extends over the entire work width, i.e. the maximal width ofthe paper or cardboard web 1 to be wound. The paper or cardboard web 1is divided into individual webs by a longitudinal cutter, which in theembodiment of FIG. 3 are guided into the roller bed through the gapbetween the carrying rollers 19, 20, where they are wound onto rows ofaligned winding cores 21. Above the roller bed in the frame of thewinding machine a pressure roller system is arranged, which comprises apressure roller 22 supported to run freely. At the start of the windingprecess, when the weight of the winding rolls 3 borne by the carryingrollers 19, 20 is not sufficient for obtaining the desired windinghardness, it is possible to increase the weight of winding roller 3borne by the carrying rollers 19, 20 by means of the pressure rollers 22pressing from above. On each side of the machine a guide head issupported vertically movable, each being introduced from the outsideinto the core 21 of the marginal roll, in order to laterally guide theset of winding rolls 3 during winding.

The two carrying rollers 19, 20 have a diameter of 300 mm to 1000 mm.Their axial length depending on the width of the paper or cardboard web1 can amount up to 10 m. The incoming side of the carrying roller 19 hasa steel shell, which can be coated with an elastically deformablerunning layer made of a solid elastomer, such as rubber. It has theprimary task to guide each individual web 1 into the roller nip formedwith the respective winding roll 3 and to prevent the introduction ofair into the winding rolls 3. Additionally in the roller nip between thecarrying roller 19 and the winding roll 3 the desired winding hardnessis produced through nip-induced stretching. In order to fulfill thisfunction, the coating of the carrying layer 19 is notvolume-compressible.

The second carrying roller 20 serving as a support roller consists of acarrying body 23 shaped as a hollow cylinder of solid material,particularly steel, on whose outer shell a volume-compressible layer 24of a cellular plastic material with a plurality of evenly distributedpores is applied. The thickness and the material characteristics of thelayer 24 correspond to the ones of the layer 20 of the additionalsupport rollers 16 of the aforedescribed winding machine with supportrollers according to FIGS. 1 and 2. The second carrying roller 20 issupported freely rotatable or connected with a rotary drive which can beswitched to free run. In case that there is a rotary drive, it servesonly for the acceleration of the carrying roller 20 when the winding isstarted, in order to synchronize its speed with the carrying roller 19,and/or to cause a hard winding start in the core area of the windingrolls 3. During winding outside of the core area of a winding roll 3 therotary drive is uncoupled. The carrying roller 20 rotates freely, sothat no torque influencing the winding hardness is generated. Duringwinding outside of the core area of a winding roll, the carrying roller20 serves exclusively for holding the winding rolls 3 in their windingposition and for bearing a part of the winding roll weight, without theinfluence of torque or the generation of a nip-induced stretching on thewinding hardness. In relation to the carrying roller 19 on the incomingside serving as a contact roller, the carrying roller 20 serving as asupport roller is arranged so that it bears between 30% and 80% of thewinding roll weight. The rest of the winding roll weight is borne by thecarrying roller 19.

The pressure roller 22 of the pressure roller system has preferably alsoa volume-compressible running layer with the characteristics of thelayer 24. It is designed as a continuous freely rotatable roller or itconsists of separate roller segments supported to rotate freely.

FIG. 4 shows a winding machine with carrying rollers wherein the web 1is guided into nips between the carrying roller 19 and the winding rolls3 from the top, being only slightly wrapped around the carrying roller19 on the incoming side. The modified web feeding leads to the fact thatthe rotation direction of the carrying rollers 19, 20, of the windingrolls 3 and of the pressure roller 22 is opposite to the rotationdirection in the winding machine with carrying rollers shown in FIG. 3.Otherwise the construction of this winding machine with carrying rollerscorresponds to the construction of the winding machine with carryingrollers according to FIG. 3.

In FIG. 5 a further embodiment of a winding machine with carryingrollers is described, wherein a second support roller 25 is arranged asa third carrying roller next to the first carrying roller 19 serving ascontact roller, on the side opposite to the second carrying roller 20.The construction of the third carrying roller 25 corresponds to theconstruction of the second carrying roller 20. It also comprises arunning layer 24 of a volume-compressible plastic material. It is alsofreely rotatable connected with a rotary drive which can be uncoupled,so that it can be switched to free running. The third carrying roller 25forms with the first carrying roller 19 a second roller bed, whereinevery second winding roll is wound up. In order to be able to enhancethe contact weight of the winding rolls 3 of each winding line, thepressure roller system comprises two freely rotatable pressure rollers22, 26, each of them being applicable to the apex lines of the windingrolls of one winding line. Thereby the second pressure roller 26corresponds in construction and function to the first pressure roller22, which is described in the embodiment example of FIG. 3.

What is claimed is:
 1. A winding machine for winding a material web intowinding rolls comprising: at least one contact roller supporting saidwinding rolls from below; means for rotating the winding rolls forproducing a tensile stress in the web during winding, said contactroller lying against the winding rolls under pressure, the web being fedto the winding rolls; and at least one additional support roller isarranged underneath the winding rolls for taking up at least a part of awinding roll weight said support roller extending axially parallel tothe contact roller, being supported to be freely rotatable or beingswitchable to be free running, and having on an outer shell periphery adeformable layer of a cellular plastic material with a plurality ofevenly distributed pores and a compression modulus κ of less than 10MPa.
 2. The winding machine according to claim 1 wherein said layerconsists of a polyurethane cellular elastomer with a compression modulusκ ranging between 1 MPa and 5 MPa.
 3. The winding machine according toclaim 1 wherein said pores are of a pore size between 0.05 mm and 1 mm.4. The winding machine according to claim 1 wherein the pores in thelayer are partially open and partially closed with a proportion of theopen pores ranging between 30% and 70%.
 5. The winding machine accordingto claim 1 wherein said layer is of a thickness ranging between 10 mm to40 mm.
 6. The winding machine according to claim 1, further comprising:a longitudinal cutter for sectioning the web into individual webs, whichare wound into separate winding rolls on respective winding cores. 7.The winding machine according to claim 6, wherein the contact roller isa driven roller against which the winding rolls rest during winding,whereby in two winding lines on both sides of the driven roller windingstations are arranged, each consisting of two carrying elements movabletransversely to a web travel direction and to which a guide headinsertable in the respective winding core is fastened.
 8. The windingmachine according to claim 7 wherein one guide head of each winding rollis connected with a rotary drive.
 9. The winding machine according toclaim 6 wherein the contact roller is a driven carrying roller, and thesupport roller is arranged as a second carrying roller axially parallelnext to the first carrying roller and extending over the length of thesame, in order to form a roller bed with the first carrying roller inwhich the winding rolls lie during winding.
 10. The winding machineaccording to claim 9 wherein a second support roller is arranged as athird carrying roller on an opposite side of the first carrying rollerfrom the second carrying roller and forms a second roller bed with thefirst carrying roller, whereby two neighboring individual webs are fedrespectively to alternate roller beds.
 11. The winding machine accordingto claim 9 wherein individual webs are guided into the roller bed frombelow, through a gap between the contact roller and the support roller.12. The winding machine according to claim 9 wherein the support rolleris arranged as a carrying roller in relation to the contact roller sothat the rollers take up between 30% and 80% of the winding roll weight.13. A winding machine for winding a material web into winding rollscomprising: at least one contact roller supporting said winding rollsfrom below; means for rotating the winding rolls for producing a tensilestress in the web during winding, said contact roller lying against thewinding rolls under pressure, the web being fed to the winding rolls;and at least one additional support roller is arranged underneath thewinding rolls for taking up at least a part of a winding roll weightsaid support roller extending axially parallel to the contact roller,being supported to be freely rotatable or being switchable to be freerunning, and having on an outer shell periphery a deformable layer of acellular plastic material with a plurality of evenly distributed poresand a compression modulus κ of less than 10 Mpa; and a longitudinalcutter for sectioning the web into individual webs, which are wound intoseparate winding rolls on respective winding cores, said contact rollerbeing a driven roller against which the winding rolls rest duringwinding, whereby in two winding lines on both sides of the driven rollerwinding stations are arranged, each consisting of two carrying elementsmovable transversely to a web travel direction and to which a guide headinsertable in the respective winding core is fastened.
 14. The windingmachine according to claim 13 wherein pressure rollers are supported onsaid cross beam swinging against the winding rolls.
 15. The windingmachine according to claim 14 wherein each support roller is supportedon a sliding carriage carrying the pressure rollers.
 16. The windingmachine according to claim 13 wherein the support rollers can be movedinto a rest position inside the crossbeam (11).